The combination pill, Moxduo, was developed by QRxPharma with the aim of decreasing dangerous side effects of prescription painkillers, including breathing problems, nausea and vomiting. The company theorized that combining lower doses of the two drugs would be safer and more effective than taking higher doses of the drugs separately.

But FDA advisers say that the company's studies of Moxduo did not show any advantages over regular oxycodone and morphine.

The FDA's 14 pain specialists all voted against approving the drug. The FDA is not required to follow the panel's recommendation.

A half-dozen public speakers urged the FDA to reject the drug at the Tuesday meeting, citing its potential for abuse.